Various surgical procedures are routinely carried out intravascularly or intraluminally. For example, in the treatment of vascular disease, such as arteriosclerosis, it is a common practice to invade the artery and insert an instrument (e.g., a balloon or other type of catheter) to carry out a procedure within the artery. Such procedures usually involve the percutaneous puncture of the artery so that an insertion sheath can be placed in the artery. The insertion sheath enables the introduction of other instruments (e.g., a catheter) to an operative position within the vascular system. Intravascular and intraluminal procedures unavoidably present the problem of stopping the bleeding at the percutaneous puncture after the procedure has been completed and after the instrument (and any insertion sheaths used therewith) has been removed. Bleeding from puncture sites, particularly in the case of femoral arterial punctures, is typically stopped by utilizing vascular closure devices, such as those described in U.S. Pat. Nos. 6,179,863; 6,090,130; and 6,045,569, which are hereby incorporated by this reference.
Typical closure devices such as the ones described in the above-mentioned patents place a sealing plug at the tissue puncture site. Successful deployment of the sealing plug, however, requires that it be manually ejected from within a device sheath and tamped down to an outer surface of the tissue puncture using a tamping tube. The tamping procedure cannot commence until the device sheath (within which the tamping tube is located) has been removed so as to expose the tamping tube for manual grasping. Under certain conditions, removal of the sheath prior to tamping the sealing plug may cause the sealing plug itself to be retracted from the tissue puncture, hindering subsequent placement of the sealing plug, and resulting in only a partial seal and associated bleeding from the tissue puncture. Accordingly, there is a need to improve the mechanism for deployment of the sealing plug at the site of a tissue puncture.